Package fj.data.fingertrees

Class Measured<V,A>

java.lang.Object

fj.data.fingertrees.Measured<V,A>

public final class Measured<V,A>
extends java.lang.Object

Determines how the elements of a tree are measured and how measures are summed. Consists of a monoid and a measuring function. Different instances of this class will result in different behaviours for the tree.

Field Summary

Fields

Modifier and Type	Field	Description
private Monoid<V>	m
private F<A,V>	measure

Constructor Summary

Constructors

Modifier	Constructor	Description
private	Measured(Monoid<V> m, F<A,V> measure)

Method Summary

Modifier and Type	Method	Description
Measured<V,Digit<V,A>>	digitMeasured()	A measured instance for digits.
F<A,V>	measure()	Returns the measuring function.
V	measure(A a)	Measures a given element.
static <V,A> Measured<V,A>	measured(Monoid<V> m, F<A,V> measure)
Monoid<V>	monoid()	Returns the monoid used to sum measures.
Measured<V,Node<V,A>>	nodeMeasured()	A measured instance for nodes.
V	sum(V a, V b)	Sums the given measurements with the monoid.
V	zero()	Returns the identity measurement for the monoid.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

m

private final Monoid<V> m

measure

private final F<A,V> measure

Constructor Detail

Measured

private Measured(Monoid<V> m,
                 F<A,V> measure)

Method Detail

measured

public static <V,A> Measured<V,A> measured(Monoid<V> m,
                                                       F<A,V> measure)

monoid

public Monoid<V> monoid()

Returns the monoid used to sum measures.

Returns:

the monoid used to sum measures.

measure

public F<A,V> measure()

Returns the measuring function.

Returns:

the measuring function.

measure

public V measure(A a)

Measures a given element.

Parameters:

a - An element to measure.

Returns:

the element's measurement.

sum

public V sum(V a,
             V b)

Sums the given measurements with the monoid.

Parameters:

a - A measurement to add to another.

b - A measurement to add to another.

Returns:

The sum of the two measurements.

zero

public V zero()

Returns the identity measurement for the monoid.

Returns:

the identity measurement for the monoid.

nodeMeasured

public Measured<V,Node<V,A>> nodeMeasured()

A measured instance for nodes.

Returns:

A measured instance for nodes.

digitMeasured

public Measured<V,Digit<V,A>> digitMeasured()

A measured instance for digits.

Returns:

A measured instance for digits.